An inkjet recording device well known in the art records print data on a recording paper by pressurizing ink in a pressurizing chamber to eject ink droplets from nozzles onto the recording paper. Many issues leading to printing inconsistencies can arise in this inkjet recording device, including viscosity build-up in the ink caused by ink solvent evaporating from the nozzles, the solidification of the ink, dust deposits, and air bubbles in the ink near the nozzles.
Therefore, this type of inkjet recording device normally has a maintenance unit including capping unit for sealing the nozzles in the recording head when not printing, and cleaning unit for cleaning a nozzle plate as needed.
For example, an ink jet recording device includes a capping unit disposed outside a printing range and including a cap that moves from a standby position to a contact position when pressed by a recording head or a carriage supporting the recording head, and a four-joint parallel linkage mechanism for moving the cap toward the nozzle plate side of the recording head as the recording head moves from the standby position to the contact position.
As shown in FIG. 1A, this capping unit 340 is configured of a cap 341 that moves vertically to seal or separate from the nozzles, a capping base 311 for supporting the cap 341, and the four-joint parallel linkage mechanism 342 for rotatably linking the cap 341 to the capping base 311. A receiving plate 344 is provided on an end portion of the cap 341 for receiving contact from the recording head 310 or carriage that pushes the cap 341.
The linking mechanism 342 includes two link members 342a and 342b with engaging holes formed on both ends thereof. An end of each link member 342a and 342b is pivotably fixed to the capping base 311, while the other end of each link member 342a and 342b is pivotably fixed to the cap 341.
As shown in FIG. 1A, a cap support part 312 is provided on the capping base 311. The cap support part 312 supports the cap 341 at a point leftward of the point at which the link member 342a in the linking mechanism 342 is engaged when the cap 341 is in the standby position, i.e. before the recording head 310 contacts the receiving plate 344 provided on the cap 341.
With this construction, the right end of the recording head 310 contacts the receiving plate 344 when the recording head 310 moves outside the printing range (toward the right in FIG. 1A). Moving farther rightward from this state, the recording head 310 pushes against the receiving plate 344 so that the cap 341 is lifted and rotated about the points on the capping base 311 to which the linking mechanism 342 is fixed, while maintaining a nozzle sealing surface (a top surface) of the cap 341 parallel to a bottom surface 310A of the recording head 310. As the cap 341 is raised, the nozzle sealing surface seals the nozzles formed in the bottom surface 310A of the recording head 310.
Conversely, when the recording head 310 moves toward the printing area (leftward in FIG. 1A), the recording head 310 no longer applies pressure to the receiving plate 344. Consequently, a spring (not shown) engaged to a lower left end of the cap 341 and the capping base 311 urges the cap 341 to return to the standby position.